This laboratory has studied the molecular basis of embryogenesis in Xenopus laevis and the zebrafish, with special emphasis on axis determination and pattern formation. These events are thought to be controlled by cell-to-cell signaling and by the spatially and temporally regulated action of transcription factors. The Xlim-1 gene encodes a LIM-homeodomain protein that has been shown to be involved in the functions of the Spemann organizer in neural induction and mesoderm patterning. This gene is also important in kidney formation. The function of Xlim-1 has been shown to involve effects on cell movements and adhesion. A screen for developmentally regulated genes has been conducted in zebrafish. By screening for genes with restricted expression patterns, valuable information is collected about gene control of embryogenesis. The role of the FGF, Wnt, BMP and retinoic acid signaling pathways in the patterning of the zebrafish nervous system has been studied. All pathways are involved in specification of the anterior-posterior patterning of the nervous system. Mechanisms regulating the FGF pathway have been studied further, and regulatory molecule including a protein phosphatase and a novel inhibitory factor named Sef have been characterized. DNA microarray technology has been introduced to study early development in zebrafish and Xenopus. These studies are currently underway